This invention relates to railroad couplers and, more particularly, to improvement in a lock element that not only reduces manufacturing costs but also enhances the dropping movement of the lock from an unlocked position to a locked position during closing of the knuckle.
The most common type of railroad coupler is an E-type railroad coupler having a horizontal key passing through a slotted opening in the side wall of the coupler shank. Other known forms of couplers include an F-type and an E/F-type wherein a vertical pin is passed through an opening in the shank of the coupler. There are many variations to these forms of couplers but each coupler is designed with the capability for either top or bottom operation by a lock-lift assembly. Different standard forms of linkage are used to move the lock element in the coupler for top and bottom modes of operation. In an E-type coupler, the lock is positioned with the capability for use in either the top or bottom mode of operation as a standard design dating back to 1931. However, during the last decade, only a small percentage of new railway cars are equipped with the suitable linkage for operation of the coupler from the top. Currently, couplers for railway vehicles are almost exclusively equipped for bottom operation. There are certain exceptions notably, for example, a relatively small percentage of couplers for locomotives.
With the foregoing in mind and the ever-present problem of reducing or at least maintaining the cost of couplers for railway vehicles within acceptable limits, it has been discovered that measures can be taken to reduce the cost of manufacturing the lock element for the coupler while at the same time improving the operation of the lock in the coupler. Heretofore, in a coupler for a railway vehicle, the lock element was manufactured from a casting with a lock-link slot and a link shaft formed as a cast structure through the use of a core and associated core-box equipment. The lock-link slot and link shaft, according to AAR standards, are located in the upper portion of the lock at the rear surface. The requirement for a core and associated core-box equipment to produce the lock-link slot and link, although rarely if ever used for the coupler operation, nevertheless consumed time and effort to workmen to clean and finish the casting. Moreover, as is known in foundry practice, when a core is used in conjunction with a patterned area, an unavoidable fin or offset occurs in the resulting casting. The fin or offset must be machined by grinding, for example, to meet standard profile requirements. Not only is manual grinding and chipping eliminated in this area of the lock, but also the required core and setting of the core to provide the link slot are eliminated. A more simplified pattern may be employed and inspection operations are reduced because gaging of the lock slot and shaft is eliminated. Also eliminated is the need to maintain a core box for the link core. While the improved lock element of the present invention brings about a realization of reduced production costs, it also enhances the operation of the coupler. The improved lock performs not only equally as well as the standard lock but also improved performance occurs particularly in regard to the essential dropping of the lock under gravity when the knuckle is moved to a locking position. In this regard, the improved lock has been found to drop more freely when the knuckle is closed, a function which is believed due to the fact that the improved lock has a weight which is increased by approximately 1.9 pounds over the weight of a standard lock and thereby changing its center of gravity more favorably.